Cooled composite piston for internal-combustion engines



July 28, 1925. 1,547,687

H. ROHWER COOLED COMPOSITE PISTON FOR INTERNAL-COMBUSTION ENGINES FiledJuly 7. 1922 7 I III 4 Patented July 28, 1925.

- umrao STATES v v t 1 547 7 PATENT OFFICE.

HEINRICH ROHWER, 055 KIEL, GERMANY, ASSIGNOR TO FRIED. KRUIBP AKTIENGE-SELLSCHAFT, GERMANIAWERFT, OF KIIZL-GAARDEN, GERMANY.

COOLED COMPOSITE PISTON FOR INTERNAL-COMBUSTION ENGINES.

Application filed July 7, 1822. SerialNo. 573,338.

To all whom it may concern.

Be it -known that I, HEINRICH RoHwnR, residing at Kiel, Germany, acitizen of the German Republic, have invented a certain trnew and usefulImprovement in Cooled Composite Pistons for Internal-Combustion Engines,of which the following is a specification. o This invention relates to apiston for inwith an inserted cooling chamber and the body of which isdivided into two parts transversally with relation to the longitudinalaxis of. the piston.

F5 The several parts of such pistons have hitherto been connected byprovidlng the base flange of the cooling chamber with outwardlyextending radial flaps serving to connect the chamber with the u perpiston part. Fitting between the sai flaps are similarly shaped inwardlyextending radial flaps of the upper division flange of the lower pistonhalf which flaps, on their part, serve to connect the two piston halveswith one another. This mode of connection is very complicated andexpensive and its influence on the strength of the piston 1s not averyfavorable one. A serious drawback of this old arrangement furtherconslsts 1n 0 that it does not permit the diameter of the cooling memberto be increased so as to cause the cylindrical portion of the chamber tobe located as close as possible to the cyllndrical portion of the upperpiston half whereby an efiicient cooling of that plston ortion cansolely be attained. ThlS draw- Back is based on the fact that the nutsof the connecting bolts interfere with each other as regards the spacethey occupy, so

circle diameters of different dimensions for the two kinds of connectingbolts.

Now, the present invention has for its object to obviate the saiddrawbacks, this object being essentially attained by arranging theabutments for the screw nuts used to connect the cooling chamber withthe upper piston part, in a transverse plane other than that in whichthe screw nuts servlng to connect the upper and lower piston parts, aresituated, so that the nuts 0 one set will not restrict the space for thenuts of the other set.

The accompanying drawing illustrates, by

be way of example, as an embodiment of the ternal combustion engineswhich is provided that it is rendered necessary to choose boltsubject-matter of the invention a vertical longitudinal section througha piston constructed in accordance with the invention.

-Wli3fl the iston head. The inserted cooling chamber die of a shapesimilar to the upper part of the piston, that means, it possesses a,cylindrical wall 0- merging into a head 0 which tits as tightly aspossible to the piston head. The fastening of the cooling chamber'tl tothe upper piston part A is performed by means of screw bolts D with theaid of the base flange c of the chamber. These connecting bolts aredisposed outwardl as far as practically possible with 'regar to thewalls of the piston parts A, A The two piston parts A and A areconnected to each other by means of screw bolts E which have. the samebolt circle diameter as the bolts D; their nuts are, however, disposedin a plane situated lower than the plane of the nuts of the bolts D andbear against an abutment provided to this end at the lower iston part A,said abutment being formed y an inwardly projecting collar a. The supplyand dischar e of the cooling medium takes place by t e channels F and G,respectively. The upper piston part A is provided with an inwardlyprojecting collar a which. is designed, on the one hand, to center thecooling chamber C and which is provided with small passage openings a,the arrangement of which will cause, on the other hand, the coolingmedium to accumulate in the hollow space situated above the collar,thereby securing a particularly efiicient cooling of the uppercorners ofsaid hollow space.

The described arran ement and construc-v efiicient cooling of thecylindrical portion of the upper piston half. Another advantage residesin that the length of the con necting bolts E caused by the describedconstruction, makes these bolts specially fit for resisting heatstresses.

I claim:

- each other, cooperating a 1. A pistonfor internal combustion enginescomprising an inserted cooling chamber and a body divided into two partstransversely with relation to the longitudinal axis of the piston, screwbolts and nuts for connecting the cooling chamber with the upper pistonpart'and the iston parts with Butments on the cooling chamber and pistonparts for the several nuts, the abutments 'for' the nuts used in theconnection of the cooling chamber with the upper piston part beingsituated' in another transverse plane than the abutments for the nutsused in the connection of thetwo piston parts with each other. i r

2. A piston for internal combustion engines comprisingan insertedcooling chamber and a body divided into two parts transversely withrelation to the longitudinal axis of the piston,-screw bolts and nutsfor connecting the cooling chamber with the up er piston part and thepiston parts with eac other, abutments on the piston parts for theseveral nuts, the abutments for the nuts used in the connectionv of thecooling chamber with theupper piston part being situated incircumferential alignment .but in another transverse plane than theabutments for the nuts used in the connection of the two piston partswith each other.

and on the cooling chamber being situated in another transverseplane'than the abutment on the other piston art and. screw bolts andnuts for connecting the cooling chamber and piston parts, some of saidbolts passing through, the abutments on both piston parts and on saidcooling chamber.

T e foregoing specification signed at this 2nd day of J une, 1922.HEINRICH- ROHWER.

Kiel, Germany,

